1. Field of the Invention
The present invention relates to product advance mechanisms such as shelf units having mechanisms for pushing products to the front of the shelf, such as for grocery store display cases, and the like.
2. Related Art
Product presentation is of utmost importance in marketing product, such as in grocery stores, hardware stores and the like, where the customer views and compares product, and chooses a particular product from a display. Product viewability, product access for the customer and product freshness, in situations of sale of perishable products, is a primary concern. Where products are perishable, product is preferably rotated so that the items on the shelves the longest are removed first, before more recently added product of the same type are selected by the customer.
Product resupply is also important to merchandisers. Shelves should be easily accessible for placing new product on a shelf. Adequate shelf space is also important to ensure proper product volume so that supply is not exhausted too quickly. Merchandisers can ensure that there is sufficient product on a shelf by including enough shelf space to be stocked to minimize the possibility of running out of product.
Several arrangements have been used to ensure that product is constantly positioned at the front of a shelf for presentation to a customer. In recent years, convenience stores have used slanted shelves for such products as canned beverages, packaged food stuffs and other product in such a manner as to permit product to advance to the front of the shelf simply by gravity so that product is always positioned at the front of the shelf. Such gravity feed shelves require more shelf space for a given amount of product relative to horizontally positioned product. However, slanted shelves provide the benefit of always having product at the front of the shelf, without requiring personnel to push stock forward toward the front of the shelf.
In addition to taking up more space relative to a comparable horizontal shelf, slanted shelves typically are suitable only for eye level locations. Eye level locations for product presented on a slanted shelf system can be easily viewed, and typically have sufficient light to allow a customer to read information on a product. However, product positioned on upper shelves may not be as easily accessible, and product on gravity feed systems below eye level are naturally slanted downward and are more difficult to view for that reason.
Product push mechanisms have been used on horizontal shelves whereby a push bracket is positioned behind aligned product and pushes the product forward as soon as a front-most product is removed from the line. The push bracket is typically biased to push product forward. Product is retained aligned on the shelf by conventional side rails or by adjacent product, and product is prevented from moving off of the shelf by a guard which extends across the front of the shelf.
Typical product push mechanisms are designed for a given product size and shape. A product push mechanism is designed according to the weight of the product, and its moveability on the shelf. The push mechanism would have a stronger bias on the push bracket for heavier product in order to move multiple items of product aligned on the shelf compared to a lighter product. If a different product were to be displayed using the same push mechanism, changes may be necessary in order to accommodate the different product, because of a difference in size or in weight, for example. A lighter product would not require as much bias on the push bracket in order to adequately advance the product to the front of the shelf. Too much bias on the push bracket could eject the front product out of the brackets or bars which contain the product. Too little bias would not adequately advance the product to the front of the shelf. Therefore, a given product push mechanism is typically suitable only for a narrow range of product weights and sizes.
If a separate product push mechanism is made for each type of product and size, manufacturing efficiencies decrease. Additionally, multiple sizes and configurations of product push mechanisms would mean that a different push mechanism would be required if a different product were to be displayed.
There is a need, therefore, for a product push mechanism which will accommodate different sizes and weights of product without having to switch out or replace the product advance mechanism in every case to accommodate a heavier product or a different sized product.